This invention relates generally to X-ray image processing and more particularly to methods and apparatus for performing a scatter correction algorithm.
At least some known imaging systems use a moving grid of parallel metal plates to facilitate a scatter-signal suppression. The grid rejects a majority of photons that are not essentially parallel to a beam emanating from an X-ray source in a direction of a detector, based on the scatter grid geometry. Since many scattered photons are not parallel to the X-ray beam, a significant proportion of scatter events are absorbed by the grid. In addition to absorbing scatter events, the grid also absorbs a significant portion of the non-scattered, or primary photons. When a scatter grid is used, approximately 20% of the remaining signal is scatter, and approximately 30% of the primary events are rejected. Scatter grid assemblies are also expensive and mechanically complex.
In one aspect, a method for removing scatter in an image is provided. The method includes acquiring data of an object of interest, and using an iterative equation including a thickness-dependent kernel modulation factor to reconstruct an image of the object.
In another aspect, a method for removing scatter in an image is provided. The method includes acquiring data of an object of interest, and using an iterative equation to reconstruct an image of the object when a scatter fraction greater than approximately 0.5.
In a further aspect, a computer readable medium encoded with a program executable by a computer for removing scatter in an image is provided. The program is configured to instruct the computer to acquire data of an object of interest, and use an iterative equation including a thickness-dependent kernel modulation factor to reconstruct an image of the object.
In a still another aspect, a medical imaging system for removing scatter in an image is provided. The medical imaging system includes a detector array, at least one radiation source, and a computer coupled to said detector array and radiation source and configured to acquire data of an object of interest, and use an iterative equation to reconstruct an image of the object when a scatter fraction is greater than approximately 0.5.